A wide variety of cameras, film cassettes, bulk film containers and the like store a long, relatively narrow filmstrip as a cylindrical film roll. (The terms "film" and "filmstrip" are used herein to refer to the same physical article. "Film" is used as the more general term. "Filmstrip" is used where it is desired to emphasize that the film, when unrolled, has the form of a long, narrow rectangle. The term "film supply" is used to refer to the camera, cassette, or container that holds the filmstrip. The roll of film is, in many cases, wound around a central spool or core. In other cases, the core is deleted in an effort to reduce expense, complexity, and weight and the film is in the form of a coreless roll or "scroll".
Scrolls can be formed by simply transporting a filmstrip into a cylindrical or similarly shaped storage container or camera film chamber. For example, a variety of cameras are known in which a film scroll is formed by prewinding unexposed film from a cartridge or spool. U.S. Pat. No. 1,921,559 and U.S. Pat. No. 1,921,560 teach thrust cartridge cameras which prewind to an empty scroll chamber having generally concave walls. This approach has the advantage that handling of the scroll is minimized, since the scroll is formed in situ. This approach has the problem that it tends to require the use of a filmstrip having specific curling properties and becomes problematic when the length of the filmstrip is increased.
A solution to this problem is using an appliance to help shape the scroll as it is formed. Scroll forming methods using appliances can be roughly categorized into methods using appliances acting external to the scroll, methods using appliances acting internal to the scroll, and methods using a combination of internal and external appliances. External-acting appliances have the advantage that the film does not need to be attached to the appliance during film scrolling. The following references teach methods and apparatus in which an external-acting appliance is used.
U.S. Pat. No. 3,057,573 teaches a camera having scroll chamber defined by three opposed rollers, which resiliently move apart as the scroll diameter is increased. One of the rollers is fixed. The other two are mounted in a movable carrier. U.S. Pat. No. 4,440,483 teaches a camera having a scroll chamber defined by curved walls and an arcuate lever. The lever is spring biased to bear against a film scroll within the chamber. U.S. Pat. No. 3,288,389 teaches the formation of a scroll in a film cartridge within a resilient band of rubber of the like. The band may be lined by foil or other flexible material. U.S. Pat. No. 2,484,248 teaches a similar cartridge having a metal spring. In each of these approaches, the film scroll is subject to the compressive force of the springs or resilient band during film use. This compressive force is undesirable, since it puts the scrolled filmstrip at risk of scratching.
U.S. Pat. No. 5,016,833 teaches a document roll-up system in which media sheets are rolled in a space defined by a pair of external guides and a "C ring". After the document has been rolled, the C ring springs out to its normal configuration. With this approach compressive force is reduced after winding; but scuffing could result due to clockspringing.
It would thus be desirable to provide a camera having a baffled supply chamber and film loading apparatus and methods in which external acting structures control film roll size throughout film winding.